X-ray makes sawmills more profitable

Published: 15 March 2017

Norra Timber is now building the world's most modern saw line at the sawmill in Sävar by installing a unique industrial computer tomography. Behind the technology shift is 30 years of research at Luleå University of Technology in Skellefteå and SP Technical Research Institute of Sweden.

– This is about a very advanced technical step, indeed the greatest advancement in the sawmill industry for the past 30 to 40 years. Here we are at the forefront of research, says Norra Timbers' CEO Pär Lärkeryd in a press release.

The CT scanner Microtec CT Log can conduct x-ray of logs at a speed of 180 meters per minute. Each stock is unique and by looking into it just before the cut, you can cut it in the most optimal way. The value of wood is expected to increase by between 4-8 %.

X-rayed logs for 30 years

Wood researchers at LTU in Skellefteå have pioneered research on the X-ray of logs. It is a similar technology used in medical tomography, and it gives a complete reconstruction of the logs' interior. Approximately 30 years of wood research has led to 20 doctoral theses. Two of these have been written by the sawmill managers Stig Grundberg and Johan Oja (also adjunct Professor at LTU) that both finished their doctorates in 1999 and have been a driving force in the development of the technology. In 2007, they won, together with Anders Grönlund, the European forestry industry's most prestigious award, "the Schweighofer Prize" for having developed a process to x-ray logs entering sawmills.

The industrial CT scanner was developed in the international research project CT-Pro which ran between 2010 and 2013. The coordinator was former SP (now called RISE – Research Institutes of Sweden) and Luleå University of Technology was one of the participants as well as Microtec, the company that is now supplying the equipment.

– It is an engineering triumph and an engineer's dream that have come true, says Anders Grönlund, Professor Emeritus of Wood Science and Engineering at Luleå University of Technology in Skellefteå.

In the video, from Norra Timber below, is a demonstration of how the revolutionary CT scanner works.